Simulation of non-recirculating flows of dilute fiber suspensions

Abstract

An elementary continuum model is used in the simulation of the flow of dilute fiber suspensions in a Newtonian fluid. A pseudo-Newton-Raphson technique is developed in which the constitutive equation is solved via a stable and accurate integration along streamlines, while the remaining equations of motion are solved by a conventional finite element method. The numerical technique is used to simulate both planar extrusion and falling-ball rheometry. In planar extrusion, simulations preduct a strong dependence of extrudate swell on fiber concentration and aspect ratio. Simulations of falling-ball rheometry predict Newtonian behavior with an intrinsic viscosity that is insensitive to initial fiber orientation.